Mobile lifting gear



July 4,1944. J. MARTIN 7 2,352,962

MOBILE LIFTING GEAR Filed June 25., 1943 4 Sheets-Sheet 1 July 4, 1944. J. MART IN 2,352,962

\ MOBILE LIFTING GEAk Filed June 25, 1945 4 Sheets-Sheet 2 per fly uw A fie/nay July 4, 1944. J, MARTIN MOBILE LIFTING GEAR I Filed June 25, 19415 4 Sheets-Sheet 3 y 1944 Y J. MARTIN 2,352,962

MOBILE LIFTING GEAR Fi'led June 25, 1943 4 Sheets-Sheet 4 Afforngy Patented July 4, 1944 MOBILE LIFTING GEAR,

James Martin, Higher Denham, near Uxbridge, England Application June 25, 1943, Serial No. 492,285 In Great Britain July 7, 1942 4 Claims.

This invention relates to mobile lifting gear or portable hoists suitable for use on aerodromes, in travelling repair shops and aircraft factories and elsewhere where it is necessary to have readily available lifting apparatus for handling heavy loads such as aere engines, aircraft wings, guns and other heavy bodies located in awkward positions. The chief object of this invention is to provide a wheeled lifting gear which is capable of withstanding rough treatment and of handling heavy loads of the character indicated whilst being easily manhandled to and from sites and being of light yet very strong form. Another object of this invention is to provide such a mobile lifting gear which is also capable of being disassembled for storage in a compact space and which can be reassembled expeditiously into a form most conveniently suited for receiving a heavy load and elevating and lowering the load with the minimum risk to operatives.

According to this invention a'mobile lifting gear comprises a winch carried by a column of skeleton girder or pedestal form with a unilateral jib at its upper end and bi-laterally spread struts at its lower end carrying at their outer or free ends wheels and combined with further wheeled supporting means of a dirigible nature to aiford a wheeled support for the column, the span of the jib'being less than that of the said struts in relation to the said column, the arrangement being that the centre of gravity of normal loads suspended from the jib is located within the lateral and fore and aft tracks of the wheels carrying the column.

In carrying one form of the invention into practice the said column is composed of tubular metal members welded together to form a skeleton column arranged vertically and strutted so as to resist bending loads transmitted thereto by a unilateral jib at its upper end. The column preferably comprises three substantially parallel tubular steel uprights with horizontal and diagonal struts welded thereto to afford a three cornered or triangulated skeleton column. Two of the uprights, which can be regarded as rear members of the column, extend below the lower end of the remaining upright which can be regarded as the apex or front member of the triangulated cross section of the column, and this front member is adapted at its lower end to serve as a socket to receive an oscillatable vertical spindle fixed at its lower end to the centre of a fork carrying a front central dirigible wheel. The rear uprights have anchored to their lower extremities a pair of tubular tension "rods which brace a pair of struts, spread outwards V fashion in relation to the column and carrying at their outer or free ends hubs for th reception of the axles of a pair of wheels. The jib is of triangulated form and in common with the said wheel carrying struts and their tension rods is disconnectable readily from the column and when disconnected can be assembled compactly within the column, the three wheels being individually removable.

In order that the invention may be clearly understood and readily carried into effect drawings are appended hereto illustrating an embodiment thereof and wherein,

Fig. 1 is a side elevation view of the complete apparatus erected for use.

Fig. 2 is a plan view of Fig. 1 showing only one half of the apparatus.

Fig. 3 is a front elevation view of Fig. 1.

Fig. 4 is a broken detail sectional elevation showing the arrangement of the detachable dirigible wheel.

Fig. 5 is a detail sectional elevation showing one of the detachable mountings for the nondirigible wheels, and

Fig. 6 is a diagrammatic end'elevation view showing how the apparatus can be stowed in a crate or box for transport and storage.

Referring to the drawings the mobile lifting gear is built about a main frame I of triangulated form and composed of three parallel metal tubes 2, 3 and 4 across which are welded horizontal and diagonal struts 5 and 6 respectively. This assembly comprises the column of the lifting gear, and it is supported on three wheels 1, 8 and 9, the wheel 1 comprising a central dirigible wheel having a pivot axis on the axis of the vertical tube 2, and the other two wheels 8 and 9 being detachably carried by the free ends of a symmetrical pair of arms, each of such arms comprising a hub housing carrying or main strut IE3 and a tension rod I I both of tubular metal. These arms l0 and are detachably connected to the uprights 3 and 4 which are prolonged downwards beyond the lower end of the central strut 2 to receive the tension rods II, the lowermost pair of diagonal struts B being fixed across the lower end of these three uprights affording a triangulated or pyramid-like sub-structure to take the compressive and tensile strains transmitted by the struts i0 and tension rods H.

The struts I0, together with their tension rods I I, are spread out V fashion, preferably with their axes in the planes joining the axes of the uprights 3 and 4 to the upright 2, as will be seen by reference to Fig. 2, the lateral span for the wheels 8 and 9 only being slightly less than the dimension joining their common aXis to the axis of the dirigible wheel I, the spacing of the wheels being such that the load suspended by a jib structure I2 at the top of the main frame I has its centre of gravity located well Within these dimensions so as to afford a stable support for the lifting apparatus and its load.

The said jib comprises a centre tension tube I4 and two rearwardly converging tubular struts I5 united to the tube I4 by parallel webs It on the struts I5 and bolts I! passed through such webs and a lug I8 at the rear end of the tension tube. A distance piece I9 is interposed between these webs to maintain them parallel and supported between their rear ends is a pulley as over which is guided the load receiving cable 2!. Another pulley ZI guides the cable from the horizontal'. track above the jib I2 to a winch 2-? se-' cured bolts 2-3 to the lower ends of the uprights 3 and 4-. This winch can be of the irreversible worm and worm wheel type driven by a crank which is removable to facilitate stor-- age of; the apparatus.

The pulley 2 l rotates between a pair of webs 26 on a hearing or bush fitted on a bolt 2? passed through bosses 2'8 welded to the tops of two upwardly' converging struts 29- which, in common with an upwardl inclined centre strut 3d, are jointed and welded to the webs 26. This centre strut 30: is, in common with the uppermost pair of horizontal struts 5, welded and jointed to a web 3I and the top ofthe upright 2, webs 32 similarly affixing these uppermost struts 5 and the struts 29 to the tops of the'uprights 3 and- 4 and also receiving bolts 33 which are passed through forked lugs on the inner ends of the jib struts 15. The tension tube Hi of the jib is formedwith a ing at its front end which is interposed between the rear corners of the webs 26 and is secured by a pair of bolts 35, so that removal of the bolts 33 and 35 enables the jib to be removed;

The dirigible wheel is supported on, an axle 31 secured across the lower ends of a tubular metal fork 38, the top-of this fork having a central upstanding spindle 39 rotatable in bushes or bearings 4!! located concentrically inside the lower end of the upright 22. A set screw M engaging in a circumferential groove in the top of this spindle locates the spindle axially and affords an easy means for releasing the spindle should it be desired to remove the fork 3'8 with the wheel I.

However it is preferred to remove the wheel I separately as well as the wheels ii and 9 so that they can all be packed in line in a crate or box as shown in Fig. 6 in which the main frame I is fitted somewhat snugly against two walls of a truncated triangular section crate 42, and the wheels E, 8 and- 9- are arranged in a line between one side of the frame I and the remaining wall of the crate, the struts and tubes I0, H, I 4 and I5 having been removed and stowed inside the main frame I. The dirigible wheel I- can be removed complete with hub 43 and axle 37! by the removal of two nuts M from two pairs of studs 45 upon which are located removable blocks 43 between which and blocks til fixed to the fork 38 are secured the ends of the axle 3'5. A locating pin 43 holds the axle against axial displacement.

The detachable connection of the struts I8 and to be handled in various situations.

effected by forming bifurcated lugs 48 on the front ends of the struts Ill and jointing and welding webs 49 to the junction of the lowermost horizontal and diagonal struts 5 and 6 and the uprights 3 and 4, the bifurcated lugs 48 and the webs 49 receiving for each strut II] a pair of bolts 49, the inclination of these webs and the bolt holes therein being arranged so as to ensure the predetermined spread and inclination of the struts Ill. The tension rods H are also formed with bifurcated lugs 50 at their ends which fit over webs 5| welded and jointed to the lowermost diagonal struts 6 and the lower ends of the uprights 3 and 4. Two pairs of bolts 52 connect the lugs 54) to the webs 5| so that the hubs of the rear wheels 8 and 9 are firmly supported by the bolted struts It! and their rods II.

The wheels 8 and 9 are detachably secured by bolts 53 to a pair of hub flanges 54 fixed to stub axles 55 rotatable in bearings 55 in two housings 51 welded to the struts If) and to webs 58 on the ends of such struts, these webs being formed with bolt holes 59 to receive bolts 63 passed through bifurcated lugs E5! on the ends of the tension rods I l. 1

The dirigible wheel I is manipulated by a traction arm or tow bar 62 of V form the limbs of which are pivoted by bolts 53 to lugs 54' forming the heads of bolts 65 passed through the blocks I M fixed. in the lower ends of the fork 38.

The mobile. lifting gear shown is particularly suited, to the requirements of aerodromes and factories where heavy loads, such as aircraft engines, wings, tanks and other heavy bodies have The apparatus can also be assembled and disassembled by the manipulation of a few bolts and nuts when it is required to transport it in a vehicle to remote sites for salvage and analogous work, or for storage and. transport. All of the main frame members, struts and stays as well as the front wheel fork are made. of tubular steel for lightness and strength.

Instead of relying upon the accommodation of V a. crate. or the like to retain the detached wheels their tension rods II to the uprights 3 and 4 is 75.

closely packed against the main frame I, the frame I can be provided, as shown in Figs. 2 and 3., with a false stud to serve as temporary fastening means for the wheel 9, said stud 55 being fastened to one of the horizontal struts 5 by means of a band 65, the stud being provided with a false hub plate 6'! fastened thereon by means of a nut 53. A similar support (not shown) for the wheel 8 can be provided on another strut 5.

I claim:

1. A mobile lifting gear comprising a triangulated main frame of tubular members including three main uprights, a triangulatedbase structure of tubular members fixed to the lower end of the frame, a dirigible wheel supported by a centre spindle engaged in the lower end of one of said uprights, two struts with tension rods detachably securod at one end to the lower ends of the other two uprights to form two symmetrical triangulated wheel carrying structures, two wheels readily detachably secured to the ends of said struts remote from said main frame, a triangulated upper structure at the top of said upright, a jib readily detachably secured to said upper structure, and a winch carried by the lower end of said main frame, the arrangement being that the said jib and said struts can be accommodated within said main frame and the wheels separately located close against one side of the main frame for storage or transport purposes.

2. A mobile lifting gear comprising a triangulated main frame in the form of three main uprights united by diagonal struts, a triangulated superstructure rigidly united to the tops of said uprights, jib forming tubular arms extending uni-laterally from said triangulated superstructure beyond one side of the main frame, the two main uprights contained by said side of the main frame depending beyond the other upright, struts and tie rods extending and diverging outwardly from the lower parts of said longer uprights, a pair of ground wheels carried by the outer ends of such diverging struts and so located that the centre of gravity of the load suspended from said jib is between the lateral span of said wheels and also between said wheels and said main frame, a centre dirigible wheel carried by the lower part of the shorter of said three main uprights, diagonal struts connected across the lower ends of the longer of said main uprights and the said shorter main upright, a winch supported by the lower ends of the said two longer uprights, and a steering arm extending from the axle of the said dirigible wheel.

3. A mobile lifting gear comprising a triangulated main frame in the form of three main uprights united by diagonal struts, a triangulated superstructure rigidly united to the tops of said uprights, jib forming tubular arms extending uni-laterally from said triangulated superstructure beyond one side of the main frame, the two main uprights contained by said side of the main frame depending beyond the other upright, struts and tie rods extending and diverging outwardly from the lower parts of said longeruprights, a pair of ground wheels carried by the outer ends of such diverging struts and so located that the centre of gravity of the load suspended from said jib is between the lateral span of said wheels and also between said wheels and said main frame, a centre dirigible wheel supported by the lower part of the shorter of said three main uprights,

diagonal struts connected across the lower ends of the longer of said main uprights and the said shorter main upright, webs welded to the junctions of said latter diagonal struts and said longer uprights and prolonged as lugs beyond said longer uprights, means detachably connecting said wheel carrying struts to said lugs, a winch supported on the lower end of said main frame, and a steering arm extending from said dirigible wheel.

4. A mobile lifting gear comprising a triangulated main frame in the form of three main uprights united by diagonal struts, a triangulated superstructure rigidly united to the tops of said uprights, jib forming tubular arms extending uni-laterally from said triangulated superstructure beyond one side of the main frame, the two main uprights contained by said side of the main frame depending beyond the other upright, struts and tie rods extending and diverging outwardly from the lower parts of said longer uprights, a pair of ground Wheels carried by the outer ends of such diverging struts and so located that the centre of gravity of the load suspended from said jib is between the lateral span of said wheels and also between said wheels and said main frame, a centre dirigible wheel supported by the lower part of the shorter of said three main uprights, diagonal struts connected across the lower ends of the longer of said main uprights and the said shorter main upright, means readily detachably connecting the wheel carrying struts to the main frame, and wheel supporting elements projecting laterally from said main frame adapted to afford temporary supporting means for the said wheels.

JAMES MARTIN. 

